Merge lines.love

Dependencies

• [2] MD3W5IRA new fork: rip out drawing support
• [3] QQBP3G6W return height of editor widget after drawing
• [4] 7VGDIPLC more robust state validation
• [5] 5STHSG4U remove some duplication
• [6] ERQKFTPV extract method
• [7] LNUHQOGH start passing in Editor_state explicitly
• [*] 2L5MEZV3 experiment: new edit namespace

Change contents

• resurrect zombie in edit.lua at line 91
  [4.366]→[3.28:52](∅→∅),[4.366]→[3.28:52](∅→∅)
  + -- return y drawn until